Three separate studies are being conducted. In the first one, phospholipid content and synthesis in blood platelets is being determined. Specific parameters being examined are phosphatidyl choline synthesis, phsophatidyl inositol synthesis, phosphatidl inositol breakdown and phospholipid profiles. In the second study, no significant differences were found in the activities of red cell Ca-ATPase activities of the two groups assayed. On the other hand, the percent activation by Na of red Ca-ATPase activity of the CF patients was significantlyn greater than that of controls. In the third study, production of cAMP was investigated in washed platelets from patients with CF, obligatory heterozygotes and controls. The CF patients and their parents did not differ from the healthy controls in cAMP response to PGE1 as a goup. However, the platelets from CF patients cAMP response to PGE1 was highly variable and correlated with plasma Alpha-tocopherol levels. Supplementation of the vitamin E deficient patients with water miscible vitamin E resulted in an increase of plasma Alpha-tocopherol and in their cAMP response to PGE1.